diff mbox series

[net-next,v7] net/ipv4: add tracepoint for icmp_send

Message ID 20240426164730214uXfxoyj3x703nsAdqnGSr@zte.com.cn (mailing list archive)
State Superseded
Headers show
Series [net-next,v7] net/ipv4: add tracepoint for icmp_send | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/apply fail Patch does not apply to net-next-1

Commit Message

xu.xin16@zte.com.cn April 26, 2024, 8:47 a.m. UTC
From: Peilin He <he.peilin@zte.com.cn>

Introduce a tracepoint for icmp_send, which can help users to get more
detail information conveniently when icmp abnormal events happen.

1. Giving an usecase example:
=============================
When an application experiences packet loss due to an unreachable UDP
destination port, the kernel will send an exception message through the
icmp_send function. By adding a trace point for icmp_send, developers or
system administrators can obtain detailed information about the UDP
packet loss, including the type, code, source address, destination address,
source port, and destination port. This facilitates the trouble-shooting
of UDP packet loss issues especially for those network-service
applications.

2. Operation Instructions:
==========================
Switch to the tracing directory.
        cd /sys/kernel/tracing
Filter for destination port unreachable.
        echo "type==3 && code==3" > events/icmp/icmp_send/filter
Enable trace event.
        echo 1 > events/icmp/icmp_send/enable

3. Result View:
================
 udp_client_erro-11370   [002] ...s.12   124.728002:
 icmp_send: icmp_send: type=3, code=3.
 From 127.0.0.1:41895 to 127.0.0.1:6666 ulen=23
 skbaddr=00000000589b167a

Change log:
===========
v6->v7:
Some fixes according to
https://lore.kernel.org/all/20240425081210.720a4cd9@kernel.org/
1. Fix patch format issues.

v5->v6:
Some fixes according to
https://lore.kernel.org/all/20240413161319.GA853376@kernel.org/
1.Resubmit patches based on the latest net-next code.

v4->v5:
Some fixes according to
https://lore.kernel.org/all/CAL+tcoDeXXh+zcRk4PHnUk8ELnx=CE2pc
Cqs7sFm0y9aK-Eehg@mail.gmail.com/
1.Adjust the position of trace_icmp_send() to before icmp_push_reply().

v3->v4:
Some fixes according to
https://lore.kernel.org/all/CANn89i+EFEr7VHXNdOi59Ba_R1nFKSBJz
BzkJFVgCTdXBx=YBg@mail.gmail.com/
1.Add legality check for UDP header in SKB.
2.Target this patch for net-next.

v2->v3:
Some fixes according to
https://lore.kernel.org/all/20240319102549.7f7f6f53@gandalf.local.home/
1. Change the tracking directory to/sys/kernel/tracking.
2. Adjust the layout of the TP-STRUCT_entry parameter structure.

v1->v2:
Some fixes according to
https://lore.kernel.org/all/CANn89iL-y9e_VFpdw=sZtRnKRu_tnUwqHu
FQTJvJsv-nz1xPDw@mail.gmail.com/
1. adjust the trace_icmp_send() to more protocols than UDP.
2. move the calling of trace_icmp_send after sanity checks
in __icmp_send().

Signed-off-by: Peilin He <he.peilin@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Yunkai Zhang <zhang.yunkai@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Liu Chun <liu.chun2@zte.com.cn>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
---
 include/trace/events/icmp.h | 68 +++++++++++++++++++++++++++++++++++++
 net/ipv4/icmp.c             |  4 +++
 2 files changed, 72 insertions(+)
 create mode 100644 include/trace/events/icmp.h

Comments

Eric Dumazet April 26, 2024, 8:55 a.m. UTC | #1
On Fri, Apr 26, 2024 at 10:47 AM <xu.xin16@zte.com.cn> wrote:
>
> From: Peilin He <he.peilin@zte.com.cn>
>
> Introduce a tracepoint for icmp_send, which can help users to get more
> detail information conveniently when icmp abnormal events happen.
>
> 1. Giving an usecase example:
> =============================
> When an application experiences packet loss due to an unreachable UDP
> destination port, the kernel will send an exception message through the
> icmp_send function. By adding a trace point for icmp_send, developers or
> system administrators can obtain detailed information about the UDP
> packet loss, including the type, code, source address, destination address,
> source port, and destination port. This facilitates the trouble-shooting
> of UDP packet loss issues especially for those network-service
> applications.
>
> 2. Operation Instructions:
> ==========================
> Switch to the tracing directory.
>         cd /sys/kernel/tracing
> Filter for destination port unreachable.
>         echo "type==3 && code==3" > events/icmp/icmp_send/filter
> Enable trace event.
>         echo 1 > events/icmp/icmp_send/enable
>
> 3. Result View:
> ================
>  udp_client_erro-11370   [002] ...s.12   124.728002:
>  icmp_send: icmp_send: type=3, code=3.
>  From 127.0.0.1:41895 to 127.0.0.1:6666 ulen=23
>  skbaddr=00000000589b167a
>
> Change log:
> ===========
> v6->v7:
> Some fixes according to
> https://lore.kernel.org/all/20240425081210.720a4cd9@kernel.org/
> 1. Fix patch format issues.
>
> v5->v6:
> Some fixes according to
> https://lore.kernel.org/all/20240413161319.GA853376@kernel.org/
> 1.Resubmit patches based on the latest net-next code.
>
> v4->v5:
> Some fixes according to
> https://lore.kernel.org/all/CAL+tcoDeXXh+zcRk4PHnUk8ELnx=CE2pc
> Cqs7sFm0y9aK-Eehg@mail.gmail.com/
> 1.Adjust the position of trace_icmp_send() to before icmp_push_reply().
>
> v3->v4:
> Some fixes according to
> https://lore.kernel.org/all/CANn89i+EFEr7VHXNdOi59Ba_R1nFKSBJz
> BzkJFVgCTdXBx=YBg@mail.gmail.com/
> 1.Add legality check for UDP header in SKB.
> 2.Target this patch for net-next.
>
> v2->v3:
> Some fixes according to
> https://lore.kernel.org/all/20240319102549.7f7f6f53@gandalf.local.home/
> 1. Change the tracking directory to/sys/kernel/tracking.
> 2. Adjust the layout of the TP-STRUCT_entry parameter structure.
>
> v1->v2:
> Some fixes according to
> https://lore.kernel.org/all/CANn89iL-y9e_VFpdw=sZtRnKRu_tnUwqHu
> FQTJvJsv-nz1xPDw@mail.gmail.com/
> 1. adjust the trace_icmp_send() to more protocols than UDP.
> 2. move the calling of trace_icmp_send after sanity checks
> in __icmp_send().
>
> Signed-off-by: Peilin He <he.peilin@zte.com.cn>
> Signed-off-by: xu xin <xu.xin16@zte.com.cn>
> Reviewed-by: Yunkai Zhang <zhang.yunkai@zte.com.cn>
> Cc: Yang Yang <yang.yang29@zte.com.cn>
> Cc: Liu Chun <liu.chun2@zte.com.cn>
> Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
> ---
>  include/trace/events/icmp.h | 68 +++++++++++++++++++++++++++++++++++++
>  net/ipv4/icmp.c             |  4 +++
>  2 files changed, 72 insertions(+)
>  create mode 100644 include/trace/events/icmp.h
>
> diff --git a/include/trace/events/icmp.h b/include/trace/events/icmp.h
> new file mode 100644
> index 000000000000..cff33aaee44e
> --- /dev/null
> +++ b/include/trace/events/icmp.h
> @@ -0,0 +1,68 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM icmp
> +
> +#if !defined(_TRACE_ICMP_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_ICMP_H
> +
> +#include <linux/icmp.h>
> +#include <linux/tracepoint.h>
> +
> +TRACE_EVENT(icmp_send,
> +
> +               TP_PROTO(const struct sk_buff *skb, int type, int code),
> +
> +               TP_ARGS(skb, type, code),
> +
> +               TP_STRUCT__entry(
> +                       __field(const void *, skbaddr)
> +                       __field(int, type)
> +                       __field(int, code)
> +                       __array(__u8, saddr, 4)
> +                       __array(__u8, daddr, 4)
> +                       __field(__u16, sport)
> +                       __field(__u16, dport)
> +                       __field(unsigned short, ulen)
> +               ),
> +
> +               TP_fast_assign(
> +                       struct iphdr *iph = ip_hdr(skb);
> +                       int proto_4 = iph->protocol;
> +                       __be32 *p32;
> +
> +                       __entry->skbaddr = skb;
> +                       __entry->type = type;
> +                       __entry->code = code;
> +
> +                       struct udphdr *uh = udp_hdr(skb);

Please move this line up., perhaps after the "struct iphdr *iph =
ip_hdr(skb);" one

We group all variable definitions together, we do not mix code and variables.



> +
> +                       if (proto_4 != IPPROTO_UDP || (u8 *)uh < skb->head ||
> +                               (u8 *)uh + sizeof(struct udphdr)
> +                               > skb_tail_pointer(skb)) {
> +                               __entry->sport = 0;
> +                               __entry->dport = 0;
> +                               __entry->ulen = 0;
> +                       } else {
> +                               __entry->sport = ntohs(uh->source);
> +                               __entry->dport = ntohs(uh->dest);
> +                               __entry->ulen = ntohs(uh->len);
> +                       }
> +
diff mbox series

Patch

diff --git a/include/trace/events/icmp.h b/include/trace/events/icmp.h
new file mode 100644
index 000000000000..cff33aaee44e
--- /dev/null
+++ b/include/trace/events/icmp.h
@@ -0,0 +1,68 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM icmp
+
+#if !defined(_TRACE_ICMP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ICMP_H
+
+#include <linux/icmp.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(icmp_send,
+
+		TP_PROTO(const struct sk_buff *skb, int type, int code),
+
+		TP_ARGS(skb, type, code),
+
+		TP_STRUCT__entry(
+			__field(const void *, skbaddr)
+			__field(int, type)
+			__field(int, code)
+			__array(__u8, saddr, 4)
+			__array(__u8, daddr, 4)
+			__field(__u16, sport)
+			__field(__u16, dport)
+			__field(unsigned short, ulen)
+		),
+
+		TP_fast_assign(
+			struct iphdr *iph = ip_hdr(skb);
+			int proto_4 = iph->protocol;
+			__be32 *p32;
+
+			__entry->skbaddr = skb;
+			__entry->type = type;
+			__entry->code = code;
+
+			struct udphdr *uh = udp_hdr(skb);
+
+			if (proto_4 != IPPROTO_UDP || (u8 *)uh < skb->head ||
+				(u8 *)uh + sizeof(struct udphdr)
+				> skb_tail_pointer(skb)) {
+				__entry->sport = 0;
+				__entry->dport = 0;
+				__entry->ulen = 0;
+			} else {
+				__entry->sport = ntohs(uh->source);
+				__entry->dport = ntohs(uh->dest);
+				__entry->ulen = ntohs(uh->len);
+			}
+
+			p32 = (__be32 *) __entry->saddr;
+			*p32 = iph->saddr;
+
+			p32 = (__be32 *) __entry->daddr;
+			*p32 = iph->daddr;
+		),
+
+		TP_printk("icmp_send: type=%d, code=%d. From %pI4:%u to %pI4:%u ulen=%d skbaddr=%p",
+			__entry->type, __entry->code,
+			__entry->saddr, __entry->sport, __entry->daddr,
+			__entry->dport, __entry->ulen, __entry->skbaddr)
+);
+
+#endif /* _TRACE_ICMP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
+
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 8cebb476b3ab..30b302492613 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -92,6 +92,8 @@ 
 #include <net/inet_common.h>
 #include <net/ip_fib.h>
 #include <net/l3mdev.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/icmp.h>

 /*
  *	Build xmit assembly blocks
@@ -762,6 +764,8 @@  void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
 	if (!fl4.saddr)
 		fl4.saddr = htonl(INADDR_DUMMY);

+	trace_icmp_send(skb_in, type, code);
+
 	icmp_push_reply(sk, &icmp_param, &fl4, &ipc, &rt);
 ende:
 	ip_rt_put(rt);